Figure 4.

Initial lung IL-1β and CXCL1 production upon B. abortus infection is dependent on caspase-1 expression. Groups of C57BL/6 WT and caspase-1/11 KO mice were intratracheally infected with 10⁶ CFU/mouse of B. abortus in 20 μl of PBS (B. ab, gray bars) or administered with 20 μl of PBS alone (NI, non-infected controls, white bars). At 2 days post-infection IL-1β (A) and CXCL1 (B) levels were quantified in lung homogenates by ELISA (n = 5 mice per group per treatment). (C) Groups of C57BL/6 WT and caspase-1/11 KO mice were intratracheally infected as described, and neutrophils counts were determined in BALF before infection (0d) and at 3 days p.i. (n = 5 mice per strain per time point). Values are means ± SD of three independent experiments (# p < 0.05, NI vs. infected within mice strains, Student's t-test; ^**p < 0.01, ^***p < 0.001, WT vs. caspase-1 KO, Student's t-test).